Roller for the drafting equipment of a spinning mill machine

ABSTRACT

A roller for drafting equipment of a spinning mill machine with an oblong cylindrical base body ( 102 ) is claimed characterized in that a hollow space ( 106 ) is provided in the base body ( 102 ). In this manner the heat transfer from the roller bearing via the base body to a roller covering on the base body can be reduced considerably. Under another aspect of the invention a roller with an oblong cylindrical base body provided with an outer roller covering essentially surrounding the circumference of the base body, whereby at least one thermally insulating layer is installed between the base body and the roller covering, serves the same purpose. In addition the invention also comprises a spinning mill machine with at least one such roller as well as a corresponding process.

[0001] The invention relates under a first aspect to a roller for the drafting equipment of a spinning mill machine with an oblong cylindrical base body.

[0002] The invention relates under a second aspect to a roller for the drafting equipment of a spinning mill machine with an oblong base body and with an outer roller covering essentially surrounding the circumference of the base body.

[0003] Under a third aspect the invention relates to a spinning mill machine with drafting equipment having upper and lower rollers.

[0004] Under a fourth aspect the invention relates to a process for the cooling of at least one roller of drafting equipment of a spinning mill machine.

[0005] When drawing fiber sliver in spinning mills, drafting equipment is used in which the fiber sliver is guided between several pairs of rollers located one after the other, each consisting of an upper and a lower roller. Since the circumferential speeds of the rollers of every roller pair accelerate in the direction of travel of the fiber sliver and since the fiber sliver is clamped along the so-called nip line of each pair of rollers, the fiber sliver is drawn in the drafting equipment.

[0006] When the machine is shut off the roller bearings are still at a very high temperature which is only insufficiently lowered—contrary to continuous operation of the machine thanks to the utilization of a blower. The heat of the bearing is transmitted to the base body of the roller and from there to the roller covering. As a result so-called roll laps may be formed, i.e. the fiber sliver or individual fibers of the fiber sliver which are still conveyed by the coasting rollers roll themselves around the rollers in question and produce interference when the machine is started up again, resulting in renewed shut-off of the machine and time-consuming removal of the roll laps.

[0007] Even if no roll laps have formed upon shutting off the machine while the roller coverings are still warm or hot during renewed running-up, the above-mentioned roll lap process with the same undesirable consequences may be produced when switching on the machine.

[0008] It is the object of the present invention to prevent the formation of roll laps in drafting equipment rollers, in particular when shutting off and/or running up the machine. In addition, easier operation of the drafting equipment should be made possible.

[0009] Furthermore this objective is attained with a roller of the type mentioned initially under its first aspect in that a hollow space is provided in the base body.

[0010] This objective is attained with a roller of the type mentioned under a second aspect in that a thermally insulating layer is provided between the base body and the roller covering.

[0011] In drafting equipment of the type mentioned initially the object of the type mentioned initially is attained under a third aspect of the invention by designing at least one roller according to the first or second aspect of the invention.

[0012] Furthermore the object in a process of the type mentioned initially under a fourth aspect of the invention is attained in that a cooling medium is conveyed through a hollow space in the (at least one) roller.

[0013] The advantages of the invention reside in particular in the fact that the heat transfer from the roller bearings via the base body to the roller covering can be reduced significantly by the hollow space according to the first aspect of the invention—if it receives a cooling medium—and by the thermally insulating layer according to the second aspect of the invention. In particular heat peaks at the bearing locations can be screened effectively thereby. The thermally insulating layer reduces the heat flow from the base roller body to the roller covering, so that the latter is extensively screened thermally. The cooling medium for its part cools the base body so that a smaller amount of heat is transferred from the base body to the roller covering.

[0014] In case that a hollow space is provided in the base body, the heat produced in drafting equipment operation in the roller coverings by the fulling operation can be diverted inward.

[0015] Especially when switching off and running up the machine, a roll lap formation can be effectively prevented through the design of at least one roller according to the invention.

[0016] It is a further advantage of the invention according to its first aspect that the hollow space results in a lower mass of the base body and that therefore less mass inertia is involved when accelerating or braking the roller in question. Consequently these acceleration and braking processes can be carried out with less energy or in shorter time spans, thus achieving savings in cost or time.

[0017] The invention according to its second aspect is especially well suited to be used with upper rollers of drafting equipment which generally are provided with a roller covering, contrary to the lower rollers. If coverings are also used on the lower rollers, the invention can also be applied in that case. The invention according to its first aspect is usable with upper as well as lower rollers, whereby the upper rollers are normally provided with the above-mentioned roller covering, but could also be designed purely as steel rollers.

[0018] To install the roller covering of the upper rollers it is state of the art technology to use an aluminum sleeve and to vulcanize a plastic layer on it. The sleeve together with the plastic layer is then pressed on the base steel body and the roller covering is then ground. The same process can be used in principle for the thermally insulated layer between base body and roller covering according to the invention, i.e. the insulating layer is first applied to the base body, e.g. glued on it, and the aluminum sleeve, generically a metal structure, is pressed on the insulating layer together with the roller covering. This is also followed by the grinding step.

[0019] Alternatively, the thermally insulating layer is applied to the inside of the metal structure or aluminum sleeve, and the sleeve together with the insulating layer on its inside and the roller covering on its outside is pressed on the base body.

[0020] The thermally insulating layer can also be applied to the base body or to the inside of the metal structure, e.g. by immersion, covering with film, vulcanization, electrostatic coating, thermal spraying, whirl sintering etc.

[0021] If necessary an axial safety device is provided for the thermally insulating layer so that it may not slip around on the base body during the operation of the machine.

[0022] The thermally insulating layer preferably contains a plastic or compound material with the required thermal characteristics for extensive suppression of heat conductivity between base body and roller covering. Thermoplastics, duroplastics, particle-reinforced compound materials, layered compound materials, fiber-reinforced compound materials and ceramics can be used here.

[0023] The roller according to the first aspect of the invention is preferably characterized in that the base body is made in form of a hollow shaft and the hollow space is essentially enclosed by the wall of the base body. This design has the advantage that relatively easy production of the base body is possible by means of inside turning. Two base body halves each with a bearing axle journal at their faces are then advantageously welded together at their other faces. Here the hollow space is preferably designed so as to be essentially asymmetric relative to the longitudinal axis of the base body.

[0024] It is furthermore a considerable advantage of the hollow shaft that the roller mass can be reduced significantly, so that lower mass inertia occurs during running up and stopping of the machine. The drafting equipment can thus be accelerated more rapidly to its normal speed, for example. In addition, the roller can return to its starting position more rapidly than the conventional heavier rollers t hanks to its lower mass inertia during vertical moves such as are triggered e.g. by thick spots in the material to be processed. The roller is thus better able to follow the contour of the fiber sliver, so that a better drawing result can be obtained.

[0025] In order to achieve the most efficient cooling possible, the hollow space extends essentially along the base body so that the heat transfer paths between cooling medium and every point of the base body's circumferential surface are as short as possible.

[0026] In a preferred embodiment of the invention under its first aspect the hollow space extends into the axle journals that are normally made in one piece with the base body. This makes it possible to achieve further mass reduction with the advantages mentioned earlier. In addition larger volumes of cooling medium can be used.

[0027] With a preferred cooling method for the base body a fluid, in particular air or water, is used as the cooling medium. A slightly condensing liquid is advantageously used, as in this case the high degree of evaporative cooling causes the base body to be cooled efficiently. The hollow space may be filled either in part or completely with a suitable liquid.

[0028] In an advantageous embodiment of the invention under its first aspect the hollow space is closed. In this case the hollow space is e.g. in essence completely inside the base body and is delimited at its face either by the sides of the base body or by the axle journals of the roller. The cooling medium is then locked into the hollow space.

[0029] Alternatively the hollow space is designed open for the passage of the cooling medium through it. This design has the advantage that the cooling medium can receive thermal energy from the base body in the hollow space and can release it again outside the base body in a heat exchanger, a cooling aggregate or similar device, so that it can then advantageously be returned to the hollow space.

[0030] In the embodiment described above, in which the hollow space extends into the axle journals, the hollow space may be open as well as closed. In case of an open hollow space, it extends axially symmetrically e.g. from the face of one of the axle journals to the face of the opposite axle journal. In this case the cooling medium can be directed through the entire roller, possibly in a circuit as described above.

[0031] In an especially preferred embodiment air, in particular air in the environment of the spinning machine, can enter the open hollow space as the cooling medium without requiring a special pumping system for the air. The air exchange alone contributes in this case to the desired heat exchange. In addition a pumping system can be provided to increase the air flow.

[0032] The cooling medium performs advantageously a double function: In addition to cooling the base body it can be used as a means to lubricate the roller bearings. For this suitable compartmentalization and corresponding passage connection from hollow space to roller bearing are required. This compartmentalization is either closed or open, whereby the cooling and lubricating medium is preferably moved in a circuit in the latter variant, with the suitably designed cooling elements being provided outside the rollers.

[0033] According to the invention, its characteristics under its first aspect (hollow space) and those under its second aspect (thermal insulating layer) can also be realized together in one and the same roller.

[0034] Advantageous further developments are characterized by the characteristics of the sub-claims.

[0035] Different examples of embodiments of the invention are explained in further detail below through the drawing.

[0036]FIG. 1 shows part of a draw frame of a spinning mill machine

[0037]FIG. 2 shows a roller of rolling equipment with a thermally insulating layer

[0038]FIG. 3 shows a roller with a closed hollow space,

[0039]FIG. 4 shows a roller with an open hollow space,

[0040]FIG. 5 shows a detail of the roller according to FIG. 4 and

[0041]FIG. 6 shows a roller with a hollow space extending into the axle journals.

[0042]FIG. 1 shows part of a known drawing frame for the drawing of a fiber sliver or fiber slivers. The important elements of the drawing frame are the drafting equipment 20, at the input side of which several sliver deflection rods 21 are provided one after the other and between which a fiber sliver F is guided and makes contact. The drafting equipment 20 itself is a so-called 4-over-3 drafting equipment with four upper rollers 22, 24, 26, 28 and three lower rollers 23, 25, 27. At the input, in the center and at the output of the drafting equipment 20 an upper roller 22, 24, 26 and a lower roller 23, 25, 27 constitute respectively an input roller pair, a central roller pair and an output roller pair. Finally in downstream direction there follows an upper roller 28 which deflects the drawn fiber sliver F in the direction of a fleece guiding nozzle 30 with an insert 31 and a downstream sliver funnel 32. The sliver funnel 32 is followed by a pair of calender roller 33 which draws off the drawn fiber sliver f from the drafting equipment 20 and deposits it by means of a rotating plate via a sliver channel into a spinning can (neither shown here). The four upper rollers 22, 24, 26, 28 are installed on a weighting arm 36 capable of being swiveled around a horizontal axis and swiveling down in a locked condition during the operation of the machine, it being possible to be swiveled up e.g. to insert a fiber sliver F. The position of the two upstream upper rollers 22, 24 is preferably adjustable while the position of the two downstream upper rollers 26, 28 supported on the weighting arm cannot be adjusted. The bearing weight of the rollers can be changed by spindles 29.

[0043] FIGS. 2 to 6 show four different embodiments of one or several upper rollers according to the invention. FIG. 2 shows an upper roller 1 with an oblong cylindrical base body 2, preferably of steel, at the two free ends of which are axle journals 10. The axle journals 10 are supported in roller bearings 11 in form of bush bearing with roll bodies 12, e.g. needles. The roller bearings 11 are themselves normally seated in matrixes. A more precise configuration of the axle journals 10 and the roller bearings 11 is not described here. These details are described exactly in DE 199 47 418.4 the disclosure of which is enclosed herewith.

[0044] The roller bearings 11 of the upper rollers 22, 24, 26 are pressed by pressing means (not shown) in the direction of the respective lower rollers 23, 25, 27 below. In this manner pressure is exerted on the fiber sliver F located between the upper roller and the lower roller, so that drawing of the fiber sliver F between the pairs of rollers is possible according to FIG. 1.

[0045] According to FIG. 2 a roller covering 5 which is stretched over a sleeve-like metal structure 4, normally made of aluminum, is installed on the outside of the base body 2. For this purpose the roller covering 5 is vulcanized e.g. on the metal structure 4 before installation on the base body 2. According to the invention a thermally insulating layer 3 is provided between the metal structure 4 and the base body 2, the insulating layer 3 being preferably made of plastic or a compound material. The layer 3 can be installed on the base body 2, whereupon the metal structure 4 together with the roller covering 5 is pressed on the base body 2 together with layer 3 in a subsequent step. Alternatively the layer 3 is installed on the side of the metal structure 4 across from the roller covering 5 and the metal structure 4 with the layer 3 on the one hand and the roller covering 5 on the other hand is pressed on the base body 2.

[0046] The layer 3 reduces the heat transfer from the base body 2 which heats up due to the rotational movement of the axle journals 10 in the roller bearings 11 to the roller covering 5. This is because the more the roller covering 5 is heated, the more likely it is that roll laps are formed around the roller 1 when the draw frame 30 is switched off or when it runs up if it had been switched off shortly before so that the temperature of the roller coverings 5 is therefore still relatively high.

[0047]FIG. 3 shows an alternative embodiment of the invention. The base body 102 of the upper roller 101 is composed of two symmetrical body parts 102 a, 102 b that are welded together at their faces by means of annular seam 109 and enclose a cylindrical hollow space 106, whereby the hollow space 106 is designed so as to be asymmetrical relative to the longitudinal axis 107 of the roller 101 and extends essentially along the entire length of the base body 102. In the embodiment of the upper roller 101 shown in FIG. 3 the hollow space 106 is closed. The long sides of the hollow space 106 are formed by the long inside of the base body 102.

[0048] The hollow space 106 reduces the mass of the roller 101 and thus makes it possible according to the invention to run up and brake the drafting equipment more rapidly. The roller 101 is also able to follow the fiber sliver contour better in lifting movements thanks to its reduced mass inertia.

[0049] In the area of one face a passage bore 108 through the base body 102 is provided through which a preferably fluid cooling medium K, e.g. air and/or water, can be conveyed from the outside into the hollow space 106. The passage bore 108 is closed by means of a suitable sealing device, e.g. with a threaded pin (not shown for the sake of clarity). The passage bore 108 can also go through part of the aluminum sleeve 4 and, in some cases, through the roller covering 5.

[0050] In an alternative embodiment not shown here the hollow space 106 is provided on at least one of its two faces with a small central opening through which the cooling medium K can be conveyed into the hollow space 106. The corresponding axle journal 10 is in this case installed on the face of the base body 102 to close off the hollow space 106.

[0051] The hollow space 106 is open in the embodiment of the invention shown in FIG. 4 and shown in detail in FIG. 5. The arrangement of axle journals is substantially as described in DE 199 47 418.4. A closing plate 123 with an axial bore 124 is provided at the face, and the closing plate 123 is provided with an annular groove 125 on the circumference to receive an O-ring 126. A stop disk 127 interacting with the axle journal 10 follows the axle journal 10. At the other end of the roll bodies or needles 12 two securing rings 128 hold within them a holding and sealing O-ring 129. Near the clothing consisting of metal structure 4 and roller covering 5 and between the bush bearings or between the roller bearing 11 and the axle journal 10, a seal 130 is provided that is impermeable to fluid media and may be made e.g. in form of a gliding seal or a labyrinth seal.

[0052] The hollow space 106 is now accessible to a fluid medium via e.g. two or four bores 120 in the axle journal 10 via intermediate spaces between the roll bodies or the needles 12 and also via grooves (not shown) in the stop disk 127 and via the central bore 124 in the closing plate 123. A hose or a pump (not shown) can be connected for example to the central bore 123 by means of which fluid media can be drawn on one side of the base body 102 into the hollow space 106 and on its other side out again. The fluid medium can thus be conveyed through the hollow space 106 in form of a circuit. Alternatively the hollow space 106 is made so as to be open only on one side which represents at the same time the input and output side for the fluid medium (not shown).

[0053] In the embodiment of FIGS. 4 and 5 the cooling medium K is conveyed along the roller bearings 11 so that the cooling medium K can also be used to lubricate the roller bearings 11, in addition to cooling the base body walls and thereby the roller covering 5. For this purpose the medium K is preferably conveyed in a circuits with a suitable external pumping system (see above), whereby external cooling elements are provided preferably to cool the medium K. Alternatively, and with a lesser cooling effect, the cooling and lubricating means K is enclosed in the roller bearings 11, in the hollow space 106 and in a suitable connection between them, such as e.g. a bore.

[0054] In the embodiment of the invention shown in FIG. 6 the hollow space 106 extends through the axle journals 10 which are mad in one piece with the two sides of the base body 102. In the embodiment shown the hollow space 106 is open and the base body 102, together with the axle journals 10 are made in one pace. At the front of the hollow space 106 hoses can be connected, leading to a pumping and cooling system (not shown). Alternatively a closed construction of the hollow space 106 can be realized, whereby two base body halves are again advantageously combined, each with an axle journal 10.

[0055] Different designs are possible for the seal between the bush bearings or roller bearings of the roller 101 according to FIG. 6. The embodiment show in FIG. 6 is the same as the one in FIG. 3 (see also DE 199 47 418.4 of the applicant). An embodiment such as for the roller of FIGS. 4 and 5 is also possible, i.e. a seal which can be made e.g. in form of gliding seal or a labyrinth seal.

[0056] The lower rollers 23, 25, 27 of drafting equipment 20 are normally hardened and chromed steel rollers with special fluting in order to achieve low-noise operation, stable drawing and low wear of the upper roller coverings 5. The hollow space 106 according to the invention can also be used with the lower rollers 23, 25, 27 of the drafting equipment 20 shown in FIG. 1 in order to achieve cooling of these rollers. 

1. Roller for drafting equipment of a spinning mill machine with an oblong cylindrical base body (102), characterized in that a hollow space (106) is provided in the base body (102).
 2. Roller as in claim 1, characterized in that the base body (102) is made in form of a hollow shaft.
 3. Roller as in claim 1 or 2, characterized in that the hollow space (106) extends essentially along the base body (102).
 4. Roller as in one of the preceding claims, characterized by a roller covering (4) essentially surrounding the outer circumference surface of the base body (102).
 5. Roller as in one of the preceding claims, characterized in that the hollow space (106) extends in axial direction through axle journals (10) connected at the faces.
 6. Roller as in one of the preceding claims, characterized in that the hollow space (106) is designed to receive a cooling medium.
 7. Roller as in one of the preceding claims, characterized in that the cooling medium (K) is a fluid, in particular water.
 8. Roller as in one of the preceding claims, characterized in that the hollow space (106) is closed.
 9. Roller as in one of the claims 1 to 7, characterized in that the hollow space (106) is open.
 10. Roller as in one of the preceding claims, characterized in that the cooling medium (K) has in addition lubricating properties and can be used in addition to cooling, at the same time for bearing lubrication of the roller bearings (11)
 11. Roller for drafting equipment of a spinning mill machine with an oblong cylindrical base body (2) and with an outer roller covering (5) essentially surrounding the circumference surface of the base body (2), characterized in that that at least one thermally insulating layer (3) is provided between the base body (2) and the roller covering (5).
 12. Roller as in claim 11, characterized in that the roller covering (5) is installed on a metal structure (4), preferably made of aluminum, which is pressed on the base body (2).
 13. Roller as in claim 11 or 12, characterized in that the layer (3) (at least one) is installed on the base body (2) or on the inside of the metal structure (4).
 14. Roller as in one of the claims 11 to 13, characterized in that the (at least one) layer (3) contains a plastic material or a compound material.
 15. Roller as in one of the claims 1 to 10 as well as according to one of the claims 11 to
 14. 16. Spinning mill machine with drafting equipment having upper and lower rollers (22, 23, 24, 25, 26, 27, 28; 1; 101) characterized in that at least one of the rollers (22, 23, 24, 25, 26, 27, 28; 1; 101) is designed according to one of the claims 1 to
 15. 17. Spinning mill machine as in claim 16, characterized by means to move the cooling medium (K) in a cricuit.
 18. Spinning mill machine as in claim 16 or 17, characterized by cooling elements located outside the rollers (22, 23, 24, 25, 26, 27, 28; 1; 101) to cool the cooling medium (K).
 19. Process for the cooling of at least one roller (22, 23, 24, 25, 26, 27, 28) of drafting equipment (20) of a spinning mill machine, characterized in that a cooling medium (K) is conveyed through a hollow space (106) in the (at least one) roller (22, 23, 24, 25, 26, 27, 28; 1; 101)
 20. Process as in claim 19, characterized in that a medium is used as the cooling medium (K) that is used at the same time for the bearing lubrication of the roller bearings (11).
 21. Process as in claim 19 or 20, characterized in that the cooling medium (K) is cooled by means of cooling elements after being conveyed through the (at least one) roller (22, 23, 24, 25, 26, 27, 28; 1; 101) and is thereupon conveyed again to at least one roller (22, 23, 24, 25, 26, 27, 28). 